An important component of any regulation of tobacco products the FDA issues is an economic analysis of the regulation. Models of the health-related economic costs of cigarette smoking have evolved and improved over the years, and current models take into account the complex relationship between smoking, health, and healthcare expenditures. However, there is a lack of research on healthcare costs attributable to the use of tobacco products other than cigarettes. It is important to have this information given the increased rates at which non-cigarette products are being used. To fill this gap, we propose to develop models to estimate the healthcare costs (i.e. healthcare expenditures) resulting from the use of different tobacco products, including cigars, moist snuff, chewing tobacco, menthol and nonmenthol cigarettes, combinations of these products, and secondhand smoke exposure. Specifically, we plan to use individual level data from national surveys to 1) develop microeconomic models to estimate the healthcare costs attributable to the use of different tobacco products to determine whether the kind of product substantially affects costs and 2) develop microeconomic models to estimate the healthcare costs attributable to secondhand smoke exposure. These models will allow us to evaluate the impact of potential FDA regulations on healthcare costs through the projected changes in tobacco product use and secondhand smoke exposure using three alternative approaches (time senes analysis with data from national surveys, longitudinal model analysis with the PATH data, and simulated changes in tobacco product use prevalence) and through incorporating mathematical simulation models of short-term risks of pulmonary and cardiovascular diseases. Our models will incorporate findings from other TCORS projects, including the impact of nsk perception on use of different tobacco products among young adults and older adults, and studies ofthe effects of tobacco products on lung injury and cardiovascular disease in the short-term. Having better models ofthe cost of smoking and models of costs associated with the use of other tobacco products will be useful for the regulation of tobacco products because policy analysis needs to consider the impact of regulations on tobacco consumption as well as costs. RELEVANCE (See instructions): We will develop, for the first time, estimates of the healthcare costs associated with the use of menthol cigarettes, cigars, moist snuff, and chewing tobacco as well as updated and improved estimates ofthe cost of cigarette smoking and secondhand smoke exposure. We will use an individual-level microeconomic cost model framework that improves upon the economic model used previously by the FDA. The models also can be used to evaluate the impact on healthcare expenditures of other policies that impact tobacco product use.